Copper Complexes of Multidentate Carboxamide Ligands.
Copper Complexes of Multidentate Carboxamide Ligands.
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DOI：
10.1016/j.ica.2018.10.011
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发表时间：
2019-01
影响因子：
2.8
通讯作者：
Courtney E Elwell;Benjamin D Neisen;W. Tolman
中科院分区：
文献类型：
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作者：
Courtney E Elwell;Benjamin D Neisen;W. Tolman
研究了两种多齿羧基配体的铜配位化学反应，分别由HL1（提供两个喹啉和一个羧基酰胺供体）和H4L2（两个吡啶（二羧基胺）单元由萘间隔剂连接）衍生。选择前者是因为在去质子化后，它将提供一个单阴离子配位的n供体集，可以模拟铜单加氧酶中假定的去质子化形式的his -支链，而后者被设计用于结合两个铜离子，并可以与其他具有不同配体间隔的系统进行比较。在与Cu(I)-mesityl反应后，hl1生成对称二聚体（L1Cu）2，其中每个双（喹啉）酰胺配体通过两个给体结合到一个Cu(I)离子上，并通过第三个与另一个Cu(I)中心结合。单体Cu（II）配合物[L1Cu(H2O)2]（OTf）和l12cu也被表征。用Cu(OTf)2和过量的Me4NOH（以CH3CN、吡啶/H2O或MeOH的形式）处理h4l2时，生成的阴离子络合物具有通式[L2Cu2(X)]n−，其中X = CH3CONH - （n = 1）、CO32 - （n = 2）或MeO−（n = 1）。这些配合物的X射线结构显示（L2）4 -配体与两个Cu（II）离子以开放的桨轮几何形式结合，另外一个桥接配体(X)完成了每个金属离子的方形平面配位球。开放桨轮图案不同于与不同间隔单元的相关配体所见的更“开放”的褶皱几何。
The copper coordination chemistry of two multidentate carboxamido ligands derived from HL1(offering two quinolyl and one carboxamide donor) and H4L2(with two pyridine(dicarboxamido) units linked by naphthalene spacers) was explored. The former was chosen because upon deprotonation it would provide a monoanionicmer-coordinatingN-donor set that would model the putative deprotonated form of the His-brace in copper monooxygenases, while the latter was designed to bind two copper ions and enable comparisons to other systems with different ligand spacers. Upon reaction with Cu(I)-mesityl, HL1yielded a symmetric dimer(L1Cu)2in which each bis(quinolyl)amide ligand binds via twoN-donors to one Cu(I) ion and via the third to the other Cu(I) center. Monomeric Cu(II) complexes [L1Cu(H2O)2](OTf) andL12Cuwere also characterized. Treatment of H4L2with Cu(OTf)2and excess Me4NOH (in CH3CN, pyridine/H2O, or MeOH) yielded complexes with anions of general formula [L2Cu2(X)]n−, where X = CH3CONH–(n = 1), CO32–(n = 2), or MeO−(n = 1). X-ray structures of these complexes revealed the (L2)4−ligand binding to two Cu(II) ions in an open paddle-wheel geometry, with an additional bridging ligand (X) completing the square planar coordination sphere of each metal ion. The open paddlewheel motif differs from the more ‘open’ puckered geometry seen with related ligands with different spacer units.